Cover crops reduce soil erosion and run-off

Water erosion

Heavy rainfall can cause soil erosion. Surface run-off occurs when excess rainfall flows across the soil surface, carrying sediment with it. This can silt up watercourses.

There is a risk of losing phosphorous from the field via run-off or sediment erosion, which can impact water quality and the environment.

Cover crops can combat soil erosion and sediment loss from surface run-off if sufficient canopy cover and root establishment are achieved.

Canopy cover prevents high-energy raindrops from hitting the soil directly. Root systems bind and stabilise the soil and improve rainwater infiltration by slowing down the flow of water and creating more soil channels.

• Soil cover of 30% can reduce run-off by 50% and erosion by up to 80%
• The best species mixtures grow rapidly in the autumn and provide good ground cover; for example, oats and brassica mixes

Maize fields can be a significant source of soil erosion. They must be actively managed to reduce the risk of soil, nutrient and agrochemical loss during winter. Cover crops oversown into maize crops can reduce overwinter losses.

The ADAS Farmscoper model helps predict the impact of sowing an autumn cover crop on nitrate, phosphorus, and sediment losses.

Wind erosion

Strong winds can blow significant amounts of soil particles off fields.

Cover crops increase surface roughness and reduce the wind speed close to the soil surface, minimising wind erosion.

Root systems also have a binding effect on the soil.